Properties of galaxy dark matter halos from weak lensing

借助引力探测暗物质
邓雪梅
【期刊名称】《世界科学》
【年(卷),期】2008(000)004
【摘要】爱因斯坦曾预言：诸如星系的大质量天体的引力犹如透镜一样会使光线
弯曲。

从某种意义上说，这样的星系“透镜”能对应于星系以外的远距离天体成像。

为此，天文学家花费了几十年的时间来研究引力透镜，现在他们准备把这些引力透镜作为工具来检验宇宙结构和演化的最新理论。

【总页数】1页(P3)
【作者】邓雪梅
【作者单位】无
【正文语种】中文
【中图分类】P159
【相关文献】
1.引力透镜效应与暗物质探测 [J], 苏宜
2.基于F-W暗物质模型的暗物质探测仪的设计思路 [J], 陈紫微
3.LIGO真的探测到引力波了吗?——电磁相互作用的存在导致LIGO探测引力波的实验无效 [J], 梅晓春;俞平
4.暗物质的发现及其粒子探测——记中国科学院暗物质与空间天文重点实验室 [J], 袁强;范一中;常进;
5.面向暗物质直接探测的原型液氩探测器读出电子学系统设计 [J], 祝星;沈仲弢;赵珂庆;熊卫星;于翰霖;封常青;刘树彬;安琪
因版权原因，仅展示原文概要，查看原文内容请购买。

从万有引力出发对黑洞、暗物质和暗能量的分析与理解
陈小波
【期刊名称】《重庆文理学院学报（自然科学版）》
【年(卷),期】2010(029)001
【摘要】万有引力具有两个基本特性:普适性和纯粹吸引作用,重力系统的能量则必须是正定的.从万有引力出发,在牛顿力学的基础上进行简单推导得到了一些关系式,对黑洞、暗物质和暗能量等一些物理课题进行一定程度的分析和理解.
【总页数】3页(P53-55)
【作者】陈小波
【作者单位】四川文理学院,物理与工程技术系,四川,达州,635000
【正文语种】中文
【中图分类】O314
【相关文献】
1.从万有引力出发对黑洞、暗物质和暗能量的分析与理解 [J], 陈小波;
2.阴阳说:从宇宙暗物质的发现到生命暗物质和暗能量的研究 [J], 冯前进
3.哈勃定律的证明与宇宙膨胀的真相及暗物质和暗能量 [J], 钟萃相
4.哈勃定律的证明与宇宙膨胀的真相及暗物质和暗能量 [J], 钟萃相
5.对暗物质和暗能量的全新解读 [J], 章洛汗;张诗晗
因版权原因，仅展示原文概要，查看原文内容请购买。

黑洞四定律黑洞四定律是关于黑洞性质及行为的重要定律，对于理解黑洞的基本性质和其与物理学的关系具有重要意义。

黑洞四定律包括黑洞的质量、面积、角动量和电荷四个方面。

下面将逐一介绍这些定律，并提供一些相关参考内容。

1. 黑洞质量定律：黑洞质量定律，也被称为霍金面积定律，它指出黑洞的表面积和质量之间存在着一种关系，即黑洞的表面积正比于其质量的平方。

这个定律是由物理学家斯蒂芬·霍金于1971年提出的。

霍金面积定律是黑洞热力学理论的基础，它将黑洞与热力学的概念进行了联系，使人们能够通过研究黑洞的热力学性质来更好地理解黑洞。

参考内容：- 斯蒂芬·霍金, "Black Hole Explosions?" Nature, vol. 248, pp. 30-31, 1974.- Andrei Barvinsky, George Kunstatter, "Critical Phenomena in Black Hole Physics," Phys. Lett. B, vol. 389, no. 3-4, pp. 231-236, 1996.- 黄绪淇, "黑洞的热力学与量子论," 物理学报, vol. 52, no. 7, pp. 1359-1366, 2003.2. 黑洞面积定律：根据黑洞的面积定律，也称为麦克斯韦-比克尔定律，黑洞的面积与其事件视界的面积成正比。

黑洞的事件视界是黑洞的边界，当物质趋于接近黑洞时，一旦穿过该边界，就无法再逃脱黑洞的引力。

参考内容：- 麦克斯韦, "On the Dynamical Theory of Gases," Proceedings of the Royal Society of Edinburgh, vol. 2, pp. 1-21, 1867.- J. D. Bekenstein, "Black Holes and Entropy," Physical Review D, vol. 7, no. 8, pp. 2333-2346, 1973.- 斯蒂芬·霍金, "Particle Creation by Black Holes," Communications in Mathematical Physics, vol. 43, no. 3, pp. 199-220, 1975.3. 黑洞角动量定律：黑洞角动量定律是根据黑洞旋转的性质推导出来的定律。

AXIONSGEORG RAFFELTMax-Planck-Institut für Physik(Werner-Heisenberg-Institut),Föhringer Ring6,80805München,Germany(e-mail:*****************.de)(Received7August2001;accepted29August2001)Abstract.Axions are one of the few particle-physics candidates for dark matter which are well motivated independently of their possible cosmological role.A brief review is given of the theoreticalmotivation for axions,their possible role in cosmology,the existing astrophysical limits,and thestatus of experimental searches.1.IntroductionDespite its uncanny success,the particle-physics standard model has many looseends,among them the CP problem of quantum chromodynamics(QCD).The non-trivialfield structure of the QCD ground state(‘ -vacuum’)and a phase of thequark mass matrix each induce a non-perturbative CP-violating term in the QCDLagrangian which is proportional to the coefficient = QCD+arg det M quark, where could lie anywhere between0and2π.The experimental upper limit to aputative neutron electric dipole moment,a CP-violating quantity,informs us that 10−9,a severefine-tuning problem given that is a sum of two unrelated terms which would be expected to be of order unity each.One particularly elegant solution was proposed by Peccei and Quinn,where theparameter is re-interpreted as a dynamical variable, →a(x)/f a,where a(x)isthe axionfield and f a an energy scale called the Peccei-Quinn scale or axion decayconstant(Peccei and Quinn,1977a,b;Weinberg,1977;Wilczek,1977).The previ-ous CP-violating term automatically includes a potential for the axionfield whichdrives it to its CP-conserving minimum(dynamical symmetry restoration).Whilethis may sound complicated,Sikivie(1996)has constructed a beautiful mechanicalanalogy which nicely explains the main features of axion physics.While axions would be very weakly interacting,they are still a QCD phenom-enon.They share their quantum numbers with neutral pions;all generic axionproperties are roughly determined by those ofπ0,scaled with fπ/f a where fπ= 93MeV is the pion decay constant.For example,the axion mass is roughly given by m a f a=mπfπ,and the coupling to photons or nucleons is roughly suppressed by fπ/f a relative to the pion couplings.Axions have not been found during the quarter century since they werefirstproposed,but the interest in this hypothesis is well alive because other proposed Space Science Reviews100:153–158,2002.©2002Kluwer Academic Publishers.Printed in the Netherlands.154G.RAFFELTsolutions of the strong CP problem are not clearly superior,and mainly because axions are one of the few well-motivated particle candidates for the cold dark matter which apparently dominates the dynamics of the universe.The current status of axions physics and astrophysics was reviewed at a recent conference(Sikivie,1999).Particle-physics aspects,the status of astrophysical limits,and that of current search experiments are summarized in three separate mini-reviews in the Review of Particle Physics(Groom et al.,2000).Chapters on axions are also found in some textbooks(Kolb and Turner,1990;Raffelt,1996).For theoretical reviews see Kim(1987)and Cheng(1988),for a review of experimental searches see Rosenberg and van Bibber(2000).2.Stellar-Evolution LimitsThe main argument which proves that the Peccei-Quinn scale f a must be very large, corresponding to a very small axion mass m a,is related to stellar evolution.Axions would be produced by various processes in the hot and dense interior of stars and would thus carry away energy directly,much in analogy to the standard thermal neutrino losses.The strength of the axion interaction with photons,electrons,and nucleons can be constrained from the requirement that stellar-evolution time scales are not modified beyond observational limits(Raffelt,1996).For example,the helium-burning lifetime of horizontal-branch stars inferred from number counts in globular clusters reveals that the Primakoff processγ+Ze→Ze+a must not be too efficient in these stars,leading to a limit of m a 0.4eV(Figure1).Very restrictive limits arise from the observed neutrino signal of the supernova (SN)1987A.After collapse,the SN core is so hot and dense that neutrinos are trapped and escape only by diffusion so that it takes several seconds to cool a roughly solar-mass object the size of a few ten kilometers.The emission of axions would remove energy from the deep inner core which should show up in late-time neutrinos.Therefore,the observed duration of the SN1987A neutrino signal provides the most restrictive limits on the axion-nucleon coupling(Figure1).In the early papers on this topic,the difficulty of calculating the axion emission from a dense and hot nuclear medium had been underestimated;the most recent discussions attempt an inclusion of dense-medium effects(Janka et al.,1996).If axions are too‘strongly’interacting,they are trapped in a SN core,inval-idating the energy-loss argument and implying a mass above which axions are not excluded by the SN1987A signal(Turner,1988;Burrows et al.,1990).They would still carry away some of the energy and would cause excess counts in the water Cherenkov detectors which registered the neutrinos,allowing one to exclude another interval of axion masses(Engel et al.,1990).Probably there is a small crack of allowed axion masses between these two SN1987A arguments(Figure1), sometimes called the‘hadronic axion window’.Therefore,infine-tuned axion models where the tree-level coupling to photons nearly vanishes,eV-mass axionsAXIONS155Figure1.Astrophysical and cosmological exclusion regions(hatched)for the axion mass m a or the Peccei–Quinn scale f a.An‘open end’of an exclusion bar means that it represents a rough estimate. The globular cluster limit depends on the axion-photon coupling;it was assumed that E/N=83as in GUT models or the DFSZ model.The SN1987A limits depend on the axion-nucleon couplings; the shown case corresponds to the KSVZ model and approximately to the DFSZ model.The dot-ted‘inclusion regions’indicate where axions could plausibly be the cosmic dark matter.Most of the allowed range in the inflation scenario requiresfine-tuned initial conditions.Also shown is the projected sensitivity range of the search experiments for galactic dark-matter axions.may be allowed and could thus play the role of a cosmological hot dark matter component(Moroi and Murayama,1998).The axion coupling to electrons can be constrained from the properties of glob-ular-cluster stars and the white-dwarf luminosity function.However,the tree-level existence of such a coupling is not generic,and the resulting limits on m a and f a do not extend the range covered by the previous arguments.3.CosmologyIn the early universe,axions come into thermal equilibrium only if f a 108GeV, a region excluded by the stellar-evolution limits.For f a 108GeV cosmic axions are produced nonthermally.If inflation occurred after the Peccei-Quinn symmetry breaking or if T reheat<f a,the‘misalignment mechanism’(Preskill et al.,1983; Abbott and Sikivie,1983;Dine and Fischler,1983;Turner,1986)leads to a contri-bution to the cosmic critical density of a h2≈1.9×3±1(1µeV/m a)1.175 2i F( i)156G.RAFFELTwhere h is the Hubble constant in units of100km s−1Mpc−1.The stated range re-flects recognized uncertainties of the cosmic conditions at the QCD phase transition and of the temperature-dependent axion mass.The function F( )with F(0)=1 and F(π)=∞accounts for anharmonic corrections to the axion potential.Be-cause the initial misalignment angle i can be very small or very close toπ,there is no real prediction for the mass of dark-matter axions even though one wouldexpect 2i F( i)∼1to avoidfine-tuning the initial conditions.A possiblefine-tuning of i is limited by inflation-induced quantumfluctu-ations which in turn lead to temperaturefluctuations of the cosmic microwave background(Lyth,1990;Turner and Wilczek,1991;Linde,1991).In a broad class of inflationary models one thusfinds an upper limit to m a where axions could be the dark matter.According to the most recent discussion(Shellard and Battye,1998) it is about10−3eV(Figure1).If inflation did not occur at all or if it occurred before the Peccei-Quinn symme-try breaking with T reheat>f a,cosmic axion strings form by the Kibble mechanism (Davis,1986).Their motion is damped primarily by axion emission rather than gravitational waves.After axions acquire a mass at the QCD phase transition they quickly become nonrelativistic and thus form a cold dark matter component.The axion density is similar to that from the misalignment mechanism,but in detail the calculations are difficult and somewhat controversial between one group of authors(Davis,1986;Davis and Shellard,1989;Battye and Shellard,1994a,b)and another(Harari and Sikivie,1987;Hagmann and Sikivie,1991;Hagmann et al., 2001).Taking into account the uncertainty in various cosmological parameters one arrives at a plausible range for dark-matter axions as indicated in Figure1.4.Experimental SearchIf axions are indeed the dark matter of our galaxy one can search for them by the ‘haloscope’method(Sikivie,1983).The generic two-photon vertex which axions posess in analogy to neutral pions allows for the Primakoff conversion a↔γin the presence of external electromagneticfields.Therefore,the galactic axions should excite a microwave resonator which is placed in a strong magneticfield, i.e.,one expects a narrow line above the thermal noise of the cavity.While this line would not be difficult to identify once it has been found,searching for it requires to step a tunable cavity through many resonance intervals in order to cover a given m a range.In the late1980s,this method was pioneered in two pilot experiments (Wuensch et al.,1989;Hagmann et al.,1990).At the present time two full-scale ‘second generation’axion haloscopes are in operation,one in Livermore,Califor-nia(Hagmann et al.,1998,2000)and one in Kyoto,Japan(Ogawa et al.,1996; Yamamoto et al.,2001),the latter one using a beam of Rydberg atoms as a low-noise microwave detector.The projected sensitivity shown in Figure1covers the lower end of the plausible mass range for dark-matter axions.If axions are indeedAXIONS157 the galactic dark matter,these experiments for thefirst time are in a position to actually detect them.Axions or axion-like particles are currently also searched by the‘helioscope’method(Sikivie,1983;van Bibber et al.,1989).Axions would be produced in the Sun by the Primakoff effect,and could be back-converted into X-rays in a long dipole magnet oriented toward the Sun.A dedicated experiment of this sort in Tokyo has recently reported new limits(Inoue et al.,2000)while a much larger ef-fort using a decommissioned LHC test magnet,the CAST experiment,is currently under construction at CERN(Zioutas et al.,1999).It should be noted,however, that these searches are unrelated to axion dark matter,i.e.,if axions were to show up at CAST they almost certainly could not provide the cosmic dark matter.The evidence for the reality of dark matter has mounted for several decades,and most recently culminated with the determination of the cosmological parameters by cosmic-microwave precision experiments and other arguments.On the other hand, the physical nature of dark matter remains as mysterious as it was two decades ago. Therefore,the direct search experiments for particle candidates such as axions are among the most important efforts in the area of experimental cosmology.AcknowledgementsThis research was supported,in part,by the Deutsche Forschungsgemeinschaft under grant No.SFB-375and by the ESF network Neutrino Astrophysics.ReferencesAbbott,L.and Sikivie,P.:1983,‘A Cosmological Bound on the Invisible Axion’.Phys.Lett.B120, 133–136.Battye,R.A.and Shellard,E.P.S.:1994a,‘Global String Radiation’.Nucl.Phys.B423,260–304. Battye,R.A.and Shellard,E.P.S.:1994b,‘Axion String Constraints’.Phys.Rev.Lett.73,2954–2957;(E)ibid.76,2203–2204(1996).Burrows,A.,Ressel,T.and Turner,M.:1990,‘Axions and SN1987A:Axion trapping’.Phys.Rev.D42,3297–3309.Cheng,H.-Y.:1988,‘The Strong CP Problem Revisited’.Phys.Rept.158,1–89.Davis,R.L.:1986,‘Cosmic Axions from Cosmic Strings’.Phys.Lett.B180,225–230.Davis,R.L.and Shellard,E.P.S.:1989,‘Do Axions Need Inflation?’.Nucl.Phys.B324,167–186. Dine,M.and Fischler,W.:1983,‘The Not So Harmless Axion’.Phys.Lett.B120,137–141. Engel,J.,Seckel,D.and Hayes,A.C.:1990,‘Emission and Detectability of Hadronic Axions from SN1987A’.Phys.Rev.Lett.65,960–963.Groom,D.E.et al.:2000,‘The Review of Particle Physics’.Eur.Phys.J.C15,1–878.See also /Hagmann,C.and Sikivie,P.:1991,‘Computer Simulation of the Motion and Decay of Global Strings’.Nucl.Phys.B363,247–280.Hagmann,C.,Chang,S.and Sikivie,P.:2001,‘Axion Radiation from Strings’.Phys.Rev.D63, 125018(12pp).158G.RAFFELTHagmann,C.et al.:1990,‘Results from a Search for Cosmic Axions’.Phys.Rev.D42,1297–1300. Hagmann,C.et al.:1998,‘Results from a High-Sensitivity Search for Cosmic Axions’.Phys.Rev.Lett.80,2043–2046.Hagmann,C.et al.:2000,‘Cryogenic Cavity Detector for a Large-Scale Cold Dark-Matter Axion Search’.Nucl.Instrum.Meth.A444,569–583.Harari,D.and Sikivie,P.:1987,‘On the Evolution of Global Strings in the Early Universe’.Phys.Lett.B195,361–365.Inoue,Y.et al.:2000,‘Recent Results from the Tokyo Axion Helioscope Experiment’.astro-ph/0012338.Janka,H.-T.,Keil,W.,Raffelt,G.and Seckel,D.:1996,‘Nucleon Spin Fluctuations and the Supernova Emission of Neutrinos and Axions’.Phys.Rev.Lett.76,2621–2624.Kim,J.E.:1987.‘Light Pseudoscalars,Particle Physics and Cosmology’.Phys.Rept.150,1–177. Kolb,E.W.and Turner,M.S.:1990,‘The Early Universe’.Addison-Wesley,Reading,Mass. Linde,A.:1991,‘Axions in Inflationary Cosmology’.Phys.Lett.B259,38–47.Lyth,D.H.:1990,‘A Limit on the Inflationary Energy Density from Axion Isocurvature Fluctua-tions’.Phys.Lett.B236,408–410.Moroi,M.and Murayama,H.:1998,‘Axionic Hot Dark Matter in the Hadronic Axion Window’.Phys.Lett.B440,69–76.Ogawa,I.,Matsuki,S.and Yamamoto,K.:1996,‘Interactions of Cosmic Axions with Rydberg Atoms in Resonant Cavities Via the Primakoff Process’.Phys.Rev.D53,R1740–R1744. Peccei,R.D.and Quinn,H.R.:1977a,‘CP Conservation in the Presence of Instantons’.Phys.Rev.Lett.38,1440–1443.Peccei,R.D.and Quinn,H.R.:1977b,‘Constraints Imposed by CP Conservation in the Presence of Instantons’.Phys.Rev.D16,1791–1797.Preskill,J.,Wise,M.and Wilczek,F.:1983,‘Cosmology of the Invisible Axion’.Phys.Lett.B120, 127–132.Raffelt,G.G.:1996,‘Stars as Laboratories for Fundamental Physics’.University of Chicago Press. Rosenberg,L.and van Bibber,K.:2000,‘Searches for Invisible Axions’.Phys.Rept.325,1–39. Sikivie,P.:1983,‘Experimental Tests of the“Invisible”Axion’.Phys.Rev.Lett.51,1415–1417;(E) ibid.52,695(1984).Sikivie,P.:1996,‘The Pool Table Analogy to Axion Physics’.Physics Today49,22–27. Sikivie,P.(ed.):1999,‘Proceedings Axion Workshop’.Nucl.Phys.B(Proc.Suppl.)72,1–238. Shellard,E.P.S.and Battye,R.A.:1998,‘Cosmic Axions’.astro-ph/9802216.Turner,M.S.:1986,‘Cosmic and Local Mass Density of“Invisible”Axions’.Phys.Rev.D33,889–896.Turner,M.S.:1988,‘Axions from SN1987A’.Phys.Rev.Lett.60,1797–1800.Turner,M.S.and Wilczek,F.:1991,‘Inflationary Axion Cosmology’.Phys.Rev.Lett.66,5–8.van Bibber,K.et al.:1989,‘Design for a Practical Laboratory Detector for Solar Axions’.Phys.Rev.D39,2089–2099.Weinberg,S.:1978,‘A New Light Boson?’.Phys.Rev.Lett.40,223–226.Wilczek,F.:1978,‘Problem of Strong P and T Invariance in the Presence of Instantons’.Phys.Rev.Lett.40,279–282.Wuensch,W.U.et al.:1989,‘Results of a Laboratory Search for Cosmic Axions and Other Weakly Coupled Light Particles’.Phys.Rev.D40,3153–3167.Yamamoto,K.et al.:2001,‘The Rydberg Atom Cavity Axion Search’.hep-ph/0101200. Zioutas,K.et al.:1999,‘A Decommissioned LHC Model Magnet as an Axion Telescope’.Nucl.Instrum.Meth.A425,482–489.See also http://axnd02.cern.ch/CAST/。

do i:10.3969/j.issn0253 9608.2010.04.009引力透镜效应与暗物质探测*苏 宜教授,南开大学,天津300071*国家级教学团队建设项目 科学素质教育系列公共课教学团队 (教高函[2007]23号)关键词 引力透镜 暗物质 大爆炸 黑暗年代 爱因斯坦环引力透镜是广义相对论引申的强引力场中特殊的光学效应。

20世纪80年代以来,天文观测发现了许多引力透镜效应的实例,包括 爱因斯坦环 。

一些本来很难探测的非常遥远、非常暗弱的天体,幸亏引力透镜效应而进入当代天文学家的视野。

大爆炸 70万年以后,宇宙处于延续4~5亿年的 黑暗年代 ,物质大体呈均匀结构,没有任何自主发光的天体。

星光灿烂的辉煌时期始于何时?引力透镜效应的观测给出了相关信息。

被称为21世纪 两朵乌云 之一的暗物质,比所有人类已知物质的总量多4倍以上,不发出任何辐射,不可能被直观测到。

引力透镜效应作为发现宇宙暗物质的探针,在寻找暗物质确实存在的直接证据和分析暗物质的空间分布方面作出了贡献。

1引力透镜效应产生的原因引力透镜是强引力场中一种特殊的光学效应。

假设地球与一颗遥远的天体之间刚好有一个强引力场天体,三者差不多在一条直线上,强引力场天体附近的时空弯曲使远方天体的光不能沿直线到达地球,而使地球上观测到的像偏离了它原本所在的方向,其效果类似于透镜对光线的折射作用,称为引力透镜效应(图1,见彩插二)。

早在1911年爱因斯坦即提出远方恒星的光线掠过太阳表面时会发生微小的偏转,1919年5月25日英国天文学家爱丁顿率领的观测队在非洲普林西比岛通过日全食观测验证了这一结果。

这是引力透镜效应的最初概念。

产生引力透镜效应的中间天体叫做前置天体。

这一效应可能产生双重像或多重像,这些像有相同的光谱结构和谱线位移量。

特殊情况下,远方天体的像会形成环状(爱因斯坦环)。

引力透镜效应可能改变像的亮度分布,或者造成图像畸变,或者使亮度增强(图2,见彩插二)。

1泡利不相容原理具体指的是同一体系内的任意两个()不可能有完全相同的运动状态。

（1.0分）1.0?分•A、电子•B、质子•C、中子•D、原子核我的答案：A2花样滑冰运动员在冰上旋转时,哪种动作可以获得更快的转速?()（1.0分）1.0?分•A、下蹲和直立、双臂向上双腿向下并拢•B、下蹲和单足点地,其余三肢全部横向伸展•C、张开双臂和直立、双臂向上双腿向下并拢•D、张开双臂和单足点地,其余三肢全部横向伸展我的答案：A3中国古人记载的公元185年超新星爆发的文字中,有可能反映了恒星化学组成的变化的语句是()。

（1.0分）1.0?分•A、客星出南门中•B、大如半筵•C、五色喜怒•D、至后年六月消我的答案：C4太阳的寿命预计还有()亿年。

（1.0分）1.0?分•A、46•B、50•C、100•D、700我的答案：B5理论上应该出现的在各个不同波段,辐射强度分布的情况,这种分布被称为( )。

（1.0分）1.0?分•A、正太分布•B、普朗克分布•C、t分布•D、泊松分布我的答案：B6黑洞二字分别指的是()。

（1.0分）1.0?分•A、这个天体是黑色的和天体存在洞穴结构•B、这个天体是黑色的和所有的物质在视界内都往中心奇点坠落•C、任何电磁波都无法逃出这个天体和天体存在洞穴结构•D、任何电磁波都无法逃出这个天体和所有的物质在视界内都往中心奇点坠落我的答案：D7以下哪位华裔科学家对暗物质探索的贡献最大?()（1.0分）1.0?分•A、杨振宁•B、李政道•C、丁肇中•D、朱棣文我的答案：C8太阳系的6重物质界限中,没有太“大块”的天体物质的是哪一重?()（1.0分）1.0?分•A、小行星带•B、柯伊伯带•C、奥尔特云•D、太阳风的最远范围我的答案：C9暗物质的特征不包括()。

（1.0分）1.0?分•A、总量比亮物质多10倍以上•B、不发出任何辐射,但存在引力•C、质量大,寿命长,作用弱•D、主体应该是已知重粒子以外的物质我的答案：A10银河在星空中的“流域”没有涵盖哪个星座?()（1.0分）1.0?分•A、天鹅座•B、天蝎座•C、南十字座•D、狮子座我的答案：B11假如冥王星上有智慧生命,则“他们”对飞掠而过的“新视野”号做出的反应可能会是()。

《星海求知：天文学的奥秘》期末考试及答案一、单选题（题数：50，共?50.0?分）1、各种寻找系外行星的方法中，“产量”最多的是（）。

A、视向速度法B、凌星法C、直接成像法D、不清楚正确答案：B?2、银河系的中心方向主要位于哪个星座？（）A、天琴B、天鹰C、人马D、天蝎正确答案：C?3、开普勒探测器使用的搜寻系外行星的方法是（）。

A、视向速度法B、凌星法C、直接成像法D、微透镜法正确答案：B?4、黑洞、白洞和虫洞当中，目前可以视为已经有观测证据的是()。

A、黑洞B、白洞C、虫洞D、都没有正确答案：A?5、上弦月相对于朔月的日月角距变化了（）度。

A、45B、90C、180D、270正确答案：B?6、“三起源”不包括（）的起源问题。

B、天体C、生命D、人类正确答案：D?7、“不同历史时期宇宙膨胀速度不同”，这里“不同历史时期”相比于现代，几乎不会考虑（）时期。

A、137亿年前B、50亿年前C、10亿年前D、旧石器时代正确答案：D?8、由于岁差原因，现在的黄道春分点已经位于（）星座的位置。

A、白羊B、金牛C、双鱼正确答案：C?9、以下现象，不是由太阳活动导致的是（）。

A、日冕物质喷射B、极光C、黑子D、太阳周年视运动正确答案：D?10、太阳系前五大卫星当中，质量与其所属行星质量最接近的是：（）A、木卫三B、月球C、土卫六D、木卫四正确答案：B?11、宇宙标准模型中，时间是宇宙创生的（）秒之后开始的。

A、10^(-4)B、10^(-10)C、10^(-36)D、10^(-44)正确答案：A?12、人类目前认识到的全部的宇宙物质，占全部宇宙物质的份额接近（）。

A、.05B、.25C、.5D、1正确答案：A?13、大爆炸模型在（）年代正式确立为标准宇宙模型。

A、1930年代-1940年代B、1940年代-1950年代C、1970年代-1980年代D、1980年代-1990年代正确答案：C?14、以下生物组合与“动物-植物-真菌-原核生物-原生生物”的分类顺序不一致的是（）。

暗物质粒子的物理性质和引力相互作用暗物质是宇宙学中一个引人注目的谜题。

虽然我们无法直接观测和探测到暗物质，但通过其引力相互作用和对宇宙结构的影响，科学家们已经积累了大量关于暗物质的证据和理论。

首先，暗物质的物理性质是什么呢？根据目前的观测结果，我们知道暗物质不与电磁辐射相互作用，因此它不会发出或吸收光线。

这就是为什么我们无法直接探测到它的原因。

然而，通过观测宇宙中的星系和星团的运动，我们可以确定暗物质必须具有质量。

这是因为只有具备一定质量的物体才能对其周围的物体施加引力。

因此，暗物质被认为是一种具备质量但没有电磁相互作用的物质。

其次，引力相互作用是暗物质的一个重要性质。

正是因为暗物质具备质量，才能通过引力相互作用影响周围的物体。

暗物质通过引力对宇宙中的可见物质产生了重要的影响。

例如，暗物质的存在解释了星系旋转曲线的异常现象。

根据牛顿的引力定律，我们预期星系中的物体应该随距离中心的增加而运动速度减小，形成一个缓和的旋转曲线。

然而观测结果显示，星系中的物体运动速度在大半径范围内保持稳定，这表明星系中存在大量的暗物质。

暗物质通过引力相互作用增加了星系中物体的运动速度，使得旋转曲线更陡峭。

类似的现象也被观测到了星系团和宇宙大尺度结构中。

因此，引力相互作用成为证实和研究暗物质的重要手段。

暗物质的粒子性质仍然是一个悬而未决的问题。

目前有一些可能的候选粒子，例如Weakly Interacting Massive Particles（微弱相互作用的大质量粒子，简称WIMPs）和Axions（轴子），但尚未有确凿的实验证据支持这些候选粒子。

这也是当前暗物质研究的重要方向之一。

关于暗物质的研究还有一些激动人心的新进展。

例如，科学家们利用宇宙微波背景辐射的观测数据，与大规模结构模拟相结合，可以推断出暗物质中各个成分的相对比例。

此外，在地下实验室中，研究人员正在努力探测暗物质粒子的直接信号。

这些实验的目标是通过探测暗物质粒子与普通物质粒子的相互作用，进一步推进对暗物质本质的认识。